Import upstream v0.16.22, stripped

Upstream commit: 474dd0229cb20cf513036619781ed97bd8073c3f
Enterprise-only files removed or emptied: 63
Enterprise-only snippets removed: 117 in 50 files
Dangling module declarations removed: 5
Cargo edits turning enterprise off: 14
Verification: clean
Enterprise feature gates left for rebuilt features: 19 in 18 files

Produced by tools/fork/strip.py. The full report is in docs/fork/strip-reports/ on main.

tests/resources/imap-test/uidplus

@@ -0,0 +1,23 @@
+capabilities: UIDPLUS
+state: created
+
+ok select ${mailbox}
+ok append
+
+"" delete ${mailbox}2
+ok create ${mailbox}2
+
+append ${mailbox}2
+ok [appenduid $uidvalidity $uid]
+
+copy 1 ${mailbox}2
+ok [copyuid $uidvalidity $srcuid $uid2]
+
+ok select ${mailbox}2
+* ok [uidvalidity $uidvalidity]
+ok fetch 1:2 uid
+* 1 fetch (uid $uid)
+* 2 fetch (uid $uid2)
+
+ok close
+"" delete ${mailbox}2